Feasibility study of high performance field emitter pattern with the horizontally oriented carbon nanotubes by electrophoresis

For the field emitter applications, electrophoretic deposition (EPD) followed by post air annealing treatment was developed to selectively deposit the single-walled carbon nanotubes (SWNTs) pattern made of Al and SiO2 coatings. The EPD was conducted from a solution mixture of SWNTs and various dispersants or surfactants, including sodium dodecyl sulfate (SDS), hexadecyl trimethyl ammonium bromide and trictylphosphine oxide. Effects of the processing parameters of EPD and the post air annealing treatment on SWNTs dispersion, morphology, field emission (FE), and film-substrate adhesion were examined. The results indicate that the SDS is the best surfactant in terms of SWNTs dispersion and solution stability, and the EPD parameters have no significant effects on their FE and adhesion properties of the deposited films. However, a higher post annealing temperature combined with an optimum annealing time is required to improve the film-substrate adhesion, so to reduce its electrical resistance and to enhance FE properties. The high performance annealed films with negligible internal stress are made of the micro-sized islands with the horizontally oriented SWNTs between them. The results also show that the pattern made of conductive and nonconductive coatings, such as Al and SiO2, can be successfully used to deposit SWNTs pattern by EPD.